Environmental Factors Affecting the Stress Corrosion Cracking Behavior of an Aluminum-Zinc-Magnesium Alloy

2009 ◽  
pp. 363-363-19
Author(s):  
Xiuli He ◽  
Hongyu Liang ◽  
Zhifeng Yan ◽  
Rui Bai

The stress corrosion cracking behaviors of micro-arc oxidized AZ31 magnesium alloy were studied by using the slow tensile test in air and 3.5 wt.% NaCl solution. Results showed that compared with the substrate, the stress corrosion cracking susceptibility of the micro-arc oxidized specimens was obvious improved apparently in 3.5 wt.% NaCl solution, due to the good corrosion resistance of the specimens after micro-arc oxidized coating treatment. In addition, regardless of the micro-arc oxidized treatment, it was the mixed fracture in air and the cleavage fracture in 3.5 wt.% NaCl solution. The micro-arc oxidized coating had no direct effect on the fracture mechanism of the alloy. It was closely related to the nature of the material and the environment of the material servicing.


2005 ◽  
Vol 297-300 ◽  
pp. 939-944 ◽  
Author(s):  
Wu Yang ◽  
Guang Fu Li ◽  
Hao Guo ◽  
Jian Jiang Zhou ◽  
Chun Bo Huang ◽  
...  

Effects of some environmental factors on stress corrosion cracking (SCC) of pipeline steel X-70 both in near-neutral pH environments, including NS4 solution and several solutions containing main types of soil in the eastern part of China, and in high pH solution were studied by means of electrochemical measurement and slow strain rate testing (SSRT). The anodic polarization curves showed different features in near-neutral pH and high pH solutions in terms of active-passive transition behavior. In near-neutral pH solutions, the cracking mode was transgranular with the feature of quasi-cleavage, the susceptibility to SCC increased with decreasing potential, pH and temperature as well as increasing CO2, indicating a dominant mechanism of hydrogen induced cracking (HIC). In high pH solutions, the cracking behavior was similar to that in near-neutral pH solutions when the specimens were polarized at cathodic potentials, but quite different at anodic potentials. A comparison of the electrochemical behavior with the SCC potential region indicated a dominant SCC mechanism associated with anodic dissolution (AD) of X70 in high pH solution at anodic potentials. A preliminary experimental potential (E)-pH-SCC diagram has been established for X70 in near-neutral pH environments.


2011 ◽  
Vol 46 (10) ◽  
pp. 1258-1266 ◽  
Author(s):  
Juan HOU ◽  
Qunjia PENG ◽  
SHOJI Testuo ◽  
Jianqiu WANG ◽  
Wei KE ◽  
...  

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